Identifying City Shrinkage in Population and City Activity in the Middle Reaches of the Yangtze River, China

Abstract

In the context of globalization, cities have undergone a polarization of growth and shrinkage. Urban shrinkage is typically measured by a decrease in population. However, city activity is usually ignored. Accordingly, this study measured city shrinkage in the middle reaches of the Yangtze River based on whether city activities and population shrank from 2000 to 2010. This study drew on the Cobb-Douglas production function using multiple big data [such as nighttime light (NTL) data, patent data, and land transaction data] to calculate a city activity index to examine city activity. The geographically weighted regression (GWR) model was applied to explore the influencing factors of city shrinkage. Results showed the following: (1) in the area of study, 14.87% of cities experienced population loss, considering the city activities, an increase in the latter accounted for 57.36% in depopulation cities; (2) urban shrinkage spatial pattern presented the feature of “overall growth, local shrinkage”; (3) in the urban shrinkage regression model, urban spatial expansion and the increase in secondary industry population were factors that aggravated urban shrinkage. The main influencing factors of city shrinkage in the regions are different and need to be studied in-depth and meticulously in combination with the local development situation. This study plays a vital role in characterizing city activities and identifying urban shrinkage while providing a reference for urban planning and policy setting.